It is arguable if the UN actually does good. The "UN", then by name of "League of Nations" was the organisation behind the treaty of Versailles, and therefore carries at least some of the blame for causing WWII.
When it renamed itself to "United Nations", here's how it got started :
http://en.wikipedia.org/wiki/United_Nations_Operation_in_the...
I've heard this UN operation described to me by some people who survived it.
1) black revolt. Small amounts of damage occur. Police generally have things under control. The police, ultimately reports to a colonial government, so the UN feels pressured to step in, and the colonial government gets paid off to let them step in.
2) the UN "judges fairly" that a white government can't be trusted to get things right, so they have to pull out. This despite the fact that the people on the ground are overwhelmingly (black) locals, and they already had significant amounts of local authority, with promises from the colonial government for expansion of that authority. The local colonial governor and army leadership refuse to give up control because of the shear stupidity of the UN's organisation (the UN didn't think it necessary to have the police force commanded on the same continent as it was operated, and didn't even bother to respond to requests for who to turn over control to), with support from the locals.
3) UN sends in racist "peacekeepers". Their first action : shoot whatever is black and holds a gun. That turned out to be the police force, "whoops, apologies". Several blue helmet basis were accused of organising group rapes of the locals (this accusation, by the way, keeps coming back in later UN operations. They are accused of doing this in Congo, Western Sahara, Sudan, Mali and several other places. The UN does not see this as a reason to stop sending in the very same troops, and to date there have been zero convictions, except of course in local jurisdictions)
4) UN withdraws (as if they somehow didn't know what would happen next).
5) situation : the police force has been partially massacred, and is obviously no longer defending the cities, and has a serious grudge against the government. The local population up in arms because their family members got shot for being black. The rebels, of course, also up in arms because of this, as they've lost family to the UN's guns just the same. This, of course, resulted in an attack on the cities by the rebels.
6) total devastation. Tens of thousands dead. Famine and disease reign for almost 2 decades. Needless to say, the UN did not see fit to help at this point.
TLDR: A country was having problems with people from the countryside taking up arms against the cities. The UN comes n, shoots up the local police force because they're black, and pulls out.
Needless to say, you will not find this operation on their site. They have fought tooth and nail not to be held responsible (against the locals), and for the soldiers involved to go free.
The country STILL has not fully recovered from the UN action in the 1960s. Needless to say, the UN goes blameless despite everyone, including the UN itself, agreeing that they hold responsibility for significant damage (they paid for a tiny amount of it).
This is the UN, plain and simple. They are evil profiteers who don't care about anything that isn't front and center in the news. They are an organisation dedicated to paying off foreign officials, hiring their children, ... to get favours, and they keep getting accused of gang-raping the locals wherever they go in Africa, in addition to a massacre every decade or so. Political correctness uber alles, and they can obviously not concern themselves with the consequences of their actions. They should have been held responsible and disbanded for this one action alone.